\documentclass{report}
\usepackage{xepersian}
\settextfont{Yas}
\makeatletter\def\@makechapterhead#1{\vspace*{9\p@}{\parindent\z@\flushleft \normalfont\ifnum\c@secnumdepth>\m@ne\Large\bfseries\@chapapp\space\@harfi\c@chapter\par\nobreak\vskip15\p@\fi \interlinepenalty\@M\huge\bfseries#1\par\nobreak\vskip0\p@}}\makeatother
\begin{document}
\makeatletter\renewcommand*\l@chapter[2]{\ifnum\c@tocdepth>-2\relax\addpenalty{-\@highpenalty} \addvspace{4mm\@plus\p@}\setlength\@tempdima{7mm}\begingroup\parindent\z@\if@RTL\leftskip\else\rightskip\fi \@pnumwidth\parfillskip-\@pnumwidth{\leavevmode\normalsize\bfseries{فصل} #1 \hfill\hb@xt@\@pnumwidth{\hss{#2}}}\par\nobreak\global\@nobreaktrue\everypar{\global\@nobreakfalse\everypar{}} \endgroup\fi}\makeatother
\tableofcontents
\chapter{اولین}
سلام
\section{قسمت}
\end{document}